The present invention relates generally to a bicycle braking system, and more particularly to a braking disc of the bicycle system.
As shown in FIGS. 1 and 2, a braking disc assembly of the prior art comprises a hub 2, a shaft sleeve seat 3 fastened with one end of the hub 2, a disc fastening seat 4 engaged with the shaft sleeve seat 3 such that an elastic ring 6, a collar 7 and a retaining ring 8 are held between the shaft sleeve seat 3 and the disc fastening seat 4 on which a disc 5 is mounted. The elastic ring 6 and the collar 7 enable the disc 5 to remain in a floating state so as to engage the brake pieces.
Such a prior art braking disc as described above is defective in design in that the floating stroke of the disc 5 is confined by the deformabilities of the elastic ring 6 and the collar 7, thereby undermining the braking effect of the disc 5. If the elastic ring 6 and the collar 7 are caused to deform by means of compression, the disc 5 is subjected to a great lateral force which inhibits the displacement of the disc 5. When the disc 5 is pressed against by the brake pieces, the braking effect is apt to be seriously undermined by the inadequacy in displacement or floating stroke of the disc 5. In other words, the prior art braking disc has an inherent structural deficiency.
The primary objective of the present invention is to provide a braking disc which is capable of position adjustment at the time when the braking disc is clamped by the brake pieces.
In keeping with the principle of the present invention, the foregoing objective of the present invention is attained by a braking disc assembly comprising a fastening seat, a disc body, and at least two connection sets. The fastening seat is mounted on a bicycle hub and is provided with at least two clamping portions, with each having two clamping pieces. The disc body is provided in the center thereof with a receiving portion for holding the fastening seat. The connection sets are composed of a locking member, a bolt, and a spring. The fastening seat is secured to the receiving portion of the disc body by the locking member which is received in a through hole of the clamping piece of the fastening seat and a locating hole of the disc body. The bolt is engaged with an inner threaded portion of the locking member. The spring is fitted over the locking member such that the spring urges at one end thereof the disc body, and at other end thereof the fastening seat.